Problem: What do the following two equations represent? $-x+3y = 3$ $5x-15y = -15$
Putting the first equation in $y = mx + b$ form gives: $-x+3y = 3$ $3y = x+3$ $y = \dfrac{1}{3}x + 1$ Putting the second equation in $y = mx + b$ form gives: $5x-15y = -15$ $-15y = -5x-15$ $y = \dfrac{1}{3}x + 1$ The above equations turn into the same equation, so they represent equal lines.